...
BookingCenter provides real-time feeds to Google to support the Google Hotels product. Google Ads doesn’t need to access the Google Hotels feed, and BookingCenter cannot provide any API access Google Hotel feeds, as it's a secure connection between BookingCenter and Google. BookingCenter is not an advertising firm, and we can’t assist in either connecting Google Analytics (Tag Manager, Universal, GTM, etc) on either a technical level, nor consulting on the benefits of connecting these two. But it's been the case since the early 2000s that Google Ads works independently of Google Hotels, and that the Analytics interface this article defines works fine to generate the 'ROI' for ad display campaigns with no connection needed to Google Hotels.
Some ad firms state that adding a Hotel's Ad Campaign ID to our Google Hotels feed can assist in some tracking benefits, so if you wish us to do so, please issue a Support ticket and our engineers can add a Google Hotels ID to the Google Hotels feed for the specific property.
...